With a charming homemade look, the wristwatch uses tape and Sugru moldable glue to bind the Raspberry Pi Model A+ — the B+’s smaller and less powerful brother — to a touchscreen, battery, switch and power converter.

To get the venerable OS running on the Pi’s ARM-based hardware, 314Reactor used the open-source machine emulator QEMU, which provides a virtual Intel 486 machine. He used his own copy of Windows 98, from which he extracted the necessary .img file.

Full instructions for building the watch are available here, along with much of the code needed. Adding the necessary hardware to the Pi was described as “relatively painless” by 314Reactor, provided you have experience hooking up electronics to the Pi’s general-purpose input/output (GPIO) pins.

As impressive as it is to run the OS on such a cheap computer, performance is rather sluggish, with 314Reactor overclocking the speed of the Pi’s CPU to 800MHz to boost its responsiveness.

If Windows 98 doesn’t prick your interest, then there are plenty of other classic Windows OSes you can run on the Pi.

Below is Windows 3.1, 95, and the recently departed XP, all running on the Pi.

While the heavy toll of emulation slows performance of most of these operating systems, Windows 3.1 seems to run as well as it did on a computers costing hundreds of dollars in the early 1990s.